1222
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 7
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 2016
- Proper Divisor Sum (Aliquot Sum)
- 794
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 552
- Möbius Function
- -1
- Radical
- 1222
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 39
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Smallest k such that the product of q/(q-1) over the primes from prime(n) to prime(n+k-1) is greater than 2.at n=24A001276
- Primes in ternary.at n=15A001363
- Numbers of the form (p^2 - 49)/120 where p is prime.at n=39A002382
- Hexagonal pyramidal numbers, or greengrocer's numbers.at n=12A002412
- Expansion of 1/((1-x)^4*(1+x)).at n=22A002623
- a(n) = ceiling(n*phi^8), where phi is the golden ratio, A001622.at n=26A004963
- Number of fountains of n coins.at n=15A005169
- Least k such that binomial(k,n) has n or more distinct prime factors.at n=33A005733
- Oscillates under partition transform.at n=38A007212
- Inverse Moebius transform of triangular numbers.at n=44A007437
- Numbers that contain only 1's and 2's. Nonempty binary strings of length n in lexicographic order.at n=21A007931
- Coordination sequence T2 for Zeolite Code AFO.at n=23A008016
- Coordination sequence T2 for Zeolite Code BRE.at n=23A008059
- Join 2n points on a line with n arcs above the line; form graph with the arcs as nodes, joining 2 nodes when the arcs cross. a(n) is the number of cases in which the graph is a path.at n=8A008909
- Coordination sequence T7 for Zeolite Code VNI.at n=22A009913
- Numbers k such that C(k,3) = C(x,3) + C(y,3) is solvable.at n=35A010330
- Shifts 3 places right under binomial transform.at n=9A010740
- Shifts 3 places left under inverse binomial transform.at n=12A010741
- a(n) = prime(n)*(prime(n+1)-1)/2.at n=14A014303
- Even hexagonal pyramidal numbers.at n=5A015226